Biology

Physiology

While Metapod is classified as a cocoon Pokémon, it bears more of a resemblance to a serpentinechrysalis. It also has a striking resemblance to the chrysalis of the Swallowtail Butterfly. Its soft body is protected by a hard outer shell while it undergoes metamorphosis. While this shell is said to be as hard as steel, a large sudden impact could cause its vulnerable body to pop out, leaving it completely exposed. It shares many physiological and behavioral characteristics with Kakuna, Silcoon and Cascoon suggesting a possible relation between the four.

In the anime, despite its idle state it can move and battle, with several ones being able to move and attack its opponent.

Behavior

In order to conserve as much energy as possible, Metapod generally remain motionless. They can be very difficult to spot in the wild, because their green coloration helps them blend in with the treetop canopies. If an enemy discovers Metapod, it is unable to do anything other than harden its outer shell. While this is enough to deter most predators, it does not offer complete protection, as the Metapod's insides remain soft and vulnerable. Its second line of defense is to drop out of the trees using String Shot. Because of its vulnerability, Metapod evolve rapidly into their final evolutionary stage.

In Gettin' The Bugs Out, Bugsy used a Metapod against Ash for the Gym Battle. Unlike most Metapod, this one was actually able to fight back by using Tackle. Multiple other Metapod were also seen in the Azalea Gym in the same episode.

In Caterpie's Big Dilemma, Xander's Caterpie became giant-sized after eating some enhanced Rare Candies. Xander's Caterpie knocked down part of a radio tower in order to make a place for it to evolve into Metapod. It later evolved again to become a Butterfree.